In general, electronic apparatuses have been subjected to an increasing market demand for smaller size, lower cost, and high versatility at a same time. In order to meet the market demand, design rules for miniaturization of semiconductors have evolved so that a semiconductor can integrate more circuits in a smaller package. However, as miniaturization progressed, a semiconductor fabricated using such a process tends to have a relatively low withstand voltage. This tendency increases a risk of damage to an electronic apparatus due to an overvoltage mistakenly applied to a semiconductor device used in the electronic apparatus. In particular, an electronic apparatus using an AC (alternating current) adaptor faces this risk when an AC adaptor having a relatively high output voltage is mistakenly applied to the apparatus.
It is possible to make a semiconductor device capable of withstanding a relatively high AC voltage by applying a high-voltage fabrication process so as to reduce or eliminate the risk of damage to the semiconductor device due to an inappropriate connection to an AC adaptor having a relatively high AC voltage. However, such a semiconductor made through a high-voltage fabrication process would have a relatively large chip size. Moreover, it would require extra cost and time for developing a new semiconductor.